West Nickerson Street had fewer traffic collisions after it was reduced from four lanes to two with a center turn lane, Mayor Mike McGinn' office announced Thursday.

Queen Anne's Nickerson was put on a "road diet" in August 2010 from 13th Avenue to the Fremont Bridge to make it safer for bicyclists, pedestrians and drivers. A new uphill bike lane was added and two more crosswalks were painted.

Traffic collisions dropped 23 percent last year compared to a prior five-year average. And people have been driving closer to the 30-mph speed limit, too, with the average speeds now 33 mph, down from 42 mph, according to Seattle Department of Transportation data. (More statistics are highlighted in the above gallery).

McGinn announced the results Thursday during a news conference. When the $241,000 project was first announced by then-Mayor Greg Nickels, it met resistance from business, freight andinterests over concerns about losing a lane of traffic. About five percent of the daily traffic is hauling freight.

The changes in behavior happened without a big drop in how many vehicles use the road every day. About 18,500 vehicles traveled Nickerson Street each day before the road diet. That number was reduced by only about 200 vehicles after the fact.

"As our recent Road Safety Summit highlighted, all of us want to reduce collisions on city streets while working toward zero fatalities and serious injuries," McGinn said in a news release. "The first year of data is in. Nickerson is a safer street without reducing its ability to handle traffic."

Road diets improve pedestrian safety because people have fewer lanes to cross when walking across the street. Sometimes, traffic will stop for someone in a crosswalk in one lane but a driver in the outside lane doesn't see the pedestrian coming.

Road diets also create more space to share with bikes. City officials say they improve flow, which seems counter-intuitive, because traffic doesn't have to stop for vehicles turning left. The travel lane on Nickerson was widened from 12 to 13 feet.

There have been 36 road rechannelizations citywide, including not far away on Stone Way North in Fremont.